The present invention relates in general to telecommunication systems, and more particularly, to an apparatus, method and system for handoff of a mobile or wireless broadcast of information specific to a geographic region or locality.
Commuters and travelers often receive radio broadcasts for a large, metropolitan area. These broadcasts may contain information pertinent to such an entire metropolitan area, such as traffic reports during rush hour. These traffic reports, however, typically cover an entire metropolitan area, and are only available during specific broadcast intervals, such as every ten minutes. Such information is also typically very general, and may not specifically pertain or apply to the precise area in which the commuter or traveler is currently, at that moment in time.
A typical broadcast in the greater Chicago metropolitan area, for example, may include general traffic information for portions of freeways and highways in and out of downtown Chicago, along with information pertaining to traffic along highways in the suburbs and the greater tri-state area. Other geographic areas within the broadcast region of metropolitan Chicago, however, may not receive any information specifically pertinent to their geographic region. For example, a commuter in Gary, Ind. will typically receive Chicago traffic information, not traffic information relevant to the stretches of highway within the city of Gary.
In addition, such information is typically quite general, and does not include information for smaller geographic regions. For example, a commuter may want to know that traffic along a local main road is particularly slow, whereas this information is completely irrelevant to a commuter as little as a few miles away.
The related application discloses an apparatus, method and system to provide or broadcast information to a given geographic region, in which the information is also specific to that geographic region. Such information may include geographically specific information such as traffic reports, sightseeing interests, weather conditions, or any other information specific to the local geographic region. Such an apparatus, method and system should also provide different or varying information from region to region.
As a mobile unit traverses a geographic region while receiving such an information broadcast, a need may arise to handoff the broadcast session from one mobile switching center and/or transceiver to another mobile switching center and/or transceiver. As a consequence, a need remains to provide an apparatus, method and system for such handoffs of information broadcasts to mobile units. In addition, such an apparatus, method and system should be user friendly, user transparent, cost effective, and capable of implementation in existing communication systems.
In accordance with the invention disclosed in the related application, geographically specific information is broadcast over specific channels within a specific geographic region, such as within the broadcast region of a specific cellular transceiver. Such information will, in general, vary from region to region, and will vary over time. When accessed, such information is broadcast to mobile units, such as cellular telephones, which are within the given region at any given time. Such access and broadcast are preferably user initiated, by the user dialing a specific sequence or number designated by the service provider for this particular type of service.
In accordance with the present invention, specific handoff procedures for mobile information broadcasts are provided, as a mobile unit may traverse multiple geographic regions and receive different and varied information during any particular broadcast session. In addition, depending upon whether a given geographic region provides such a broadcast, a hand-off procedure may not occur, with the broadcast channel retained by the current transceiver and mobile switching center.
A new parameter, referred to herein as a xe2x80x9cbroadcast parameterxe2x80x9d, is utilized to designate that an information broadcast is to be handed off, to distinguish a broadcast handoff from a conventional communication session handoff. In the preferred embodiment, the broadcast parameter is defined as an octet (8 bits), which may be included as a new field within ANSI-compatible messages, and may have a value of zero to 255. In particular, as discussed in greater detail below, the broadcast parameter is utilized preferably in four types of ANSI messages, including Handoff Measurement Requests, Facilities Directives, Handoff Back messages, and Handoff to Third messages.
The preferred system includes a plurality of mobile switching centers coupled via signaling and trunk lines to a plurality of transceivers. The mobile broadcast is typically transmitted on a first broadcast channel from a serving switching center and a serving transceiver to a mobile unit, such as to a cellular telephone. The serving switching center selects a target switching center for the handoff of the broadcast session, preferably by transmitting a Handoff Measurement Request that includes a broadcast parameter, and receiving corresponding Handoff Measurement Request Return Results. The serving switching center then transmits a handoff directive that also includes the broadcast parameter designating the mobile broadcast. The handoff directive may be a Facilities Directives, a Handoff Back message, or a Handoff to Third message. The target switching center determines a second broadcast channel providing an information broadcast feature in a second geographic area served by the target switching center and a target transceiver. Via the serving transceiver, the serving switching center directs the mobile unit to the second broadcast channel.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.